Japanese Patent Application Publication No. 2004-108944 (hereinafter referred to as Document 1) discloses an obstacle detection device that detects an obstacle such as a vehicle or a sidewall with use of a distance meter using ultra sonic. The obstacle detection device can detect a position of an obstacle according to a distance to the obstacle detected by the distance meter using ultra sonic. And the obstacle detection device can detect a parking position of a vehicle.
Japanese Patent Application Publication No. 11-105686 (hereinafter referred to as Document 2) discloses an automatic parking device that sets a stopping position of a vehicle according to a white line recognized by an imager. The automatic parking device can determine a parking position in a parking area where an obstacle is not provided, and can move a vehicle automatically.
However, the distance meter of Document 1 has an accuracy problem of object recognition, although the distance meter can recognize an object from a relatively far point. In addition, the distance meter cannot detect the parking position accurately when the vehicle detected by the distance meter is inclined. The imager of Document 2 is affected by a recognition error caused by a step or a slope in a case where the imager takes an image of the white line from a far point, although the imager can set an accurate parking position according to the white line. That is, the recognition accuracy changes largely with a movement of a vehicle, and it is difficult to detect a timing of determining of the parking position.
The present invention provides a target position setting device and a parking assistance device having the target position setting device that can set an accurate target position at an adequate time.